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Some optimizations & fixes

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This commit is contained in:
Ilari Liusvaara 2014-05-23 04:21:00 +03:00
parent f20d522c4c
commit c5372a4826
1 changed files with 35 additions and 30 deletions
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65
src/library/curve25519.cpp
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@ -35,28 +35,22 @@ namespace
s[1] = ((wide_t)x[0] * (wide_t)x[1] << 1) + 19 * (((wide_t)x[2] * (wide_t)x[4] << 1) +
((wide_t)x[3] * (wide_t)x[3]));
s[2] = ((wide_t)x[0] * (wide_t)x[2] << 1) + ((wide_t)x[1] * (wide_t)x[1]) +
19 * ((wide_t)x[3] * (wide_t)x[4] << 1);
38 * ((wide_t)x[3] * (wide_t)x[4]);
s[3] = ((wide_t)x[0] * (wide_t)x[3] << 1) + ((wide_t)x[1] * (wide_t)x[2] << 1) +
19 * ((wide_t)x[4] * (wide_t)x[4]);
s[4] = ((wide_t)x[0] * (wide_t)x[4] << 1) + ((wide_t)x[1] * (wide_t)x[3] << 1) +
((wide_t)x[2] * (wide_t)x[2]);
s[1] += (s[0] >> shift);
s[0] &= mask;
s[2] += (s[1] >> shift);
s[1] &= mask;
x[2] = (limb_t)s[2] & mask;
s[3] += (s[2] >> shift);
s[2] &= mask;
x[3] = (limb_t)s[3] & mask;
s[4] += (s[3] >> shift);
s[3] &= mask;
s[0] += 19 * (s[4] >> shift);
s[4] &= mask;
s[1] += s[0] >> shift;
s[0] &= mask;
x[0] = s[0];
x[1] = s[1];
x[2] = s[2];
x[3] = s[3];
x[4] = s[4];
x[4] = (limb_t)s[4] & mask;
s[0] = ((limb_t)s[0] & mask) + 19 * (limb_t)(s[4] >> shift);
x[0] = (limb_t)s[0] & mask;
s[1] = ((limb_t)s[1] & mask) + (limb_t)(s[0] >> shift);
x[1] = (limb_t)s[1];
}
memcpy(n, x, sizeof(x));
zeroize(x, sizeof(x));
@ -82,22 +76,16 @@ namespace
(wide_t)a.n[2] * (wide_t)b.n[2] + (wide_t)a.n[3] * (wide_t)b.n[1] +
(wide_t)a.n[4] * (wide_t)b.n[0];
s[1] += (s[0] >> shift);
s[0] &= mask;
s[2] += (s[1] >> shift);
s[1] &= mask;
n[2] = (limb_t)s[2] & mask;
s[3] += (s[2] >> shift);
s[2] &= mask;
n[3] = (limb_t)s[3] & mask;
s[4] += (s[3] >> shift);
s[3] &= mask;
s[0] += 19 * (s[4] >> shift);
s[4] &= mask;
s[1] += s[0] >> shift;
s[0] &= mask;
n[0] = s[0];
n[1] = s[1];
n[2] = s[2];
n[3] = s[3];
n[4] = s[4];
n[4] = (limb_t)s[4] & mask;
s[0] = ((limb_t)s[0] & mask) + 19 * (limb_t)(s[4] >> shift);
n[0] = (limb_t)s[0] & mask;
s[1] = ((limb_t)s[1] & mask) + (limb_t)(s[0] >> shift);
n[1] = (limb_t)s[1];
zeroize(s, sizeof(s));
}
//e - self -> self
@ -146,7 +134,7 @@ namespace
}
for(unsigned i = 0; i < 32; i++) {
buffer[i] = n[8 * i / shift] >> (8 * i % shift);
if(8 * i % shift > shift - 8)
if(8 * i % shift > shift - 8 && i < 26)
buffer[i] |= n[8 * i / shift + 1] << (shift - 8 * i % shift);
}
}
@ -157,7 +145,7 @@ namespace
for(unsigned i = 0; i < 32; i++) {
n[8 * i / shift] |= (limb_t)buffer[i] << (8 * i % shift);
n[8 * i / shift] &= mask;
if(8 * i % shift > shift - 8) {
if(8 * i % shift > shift - 8 && i < 26) {
n[8 * i / shift + 1] |= (limb_t)buffer[i] >> (shift - 8 * i % shift);
}
}
@ -527,6 +515,13 @@ const uint8_t curve25519_base[32] = {9};
/*
uint64_t arch_get_tsc()
{
uint32_t a, b;
asm volatile("rdtsc" : "=a"(a), "=d"(b));
return ((uint64_t)b << 32) | a;
}
//For comparision
extern "C"
{
@ -539,6 +534,16 @@ int main()
FILE* fd = fopen("/dev/urandom", "rb");
uint64_t ctr = 0;
buf[32] = 9;
fread(buf, 1, 32, fd);
buf[0] &= 248;
buf[31] &= 127;
buf[31] |= 64;
uint64_t t = arch_get_tsc();
for(unsigned i = 0; i < 10000; i++) {
curve25519(buf+64, buf, buf+32);
}
t = arch_get_tsc() - t;
std::cerr << "Avg: " << t / 10000 << std::endl;
while(true) {
fread(buf, 1, 32, fd);
buf[0] &= 248;
@ -574,4 +579,4 @@ int main()
std::cerr << "Passed " << ctr << " tests." << std::endl;
}
}
*/
*/